DHCPv4
Server
DHCP DISCOVER
DHCP OFFER
DHCPv4
Client
DHCP REQUEST
DHCP ACK
Multiple servers can
reply to DHCP
discover message.
The client accepts
only one offer by
requesting this
address.
DHCP REQUEST
DHCP ACK
The renew
performed by
requests to continue
using the IP
address.
Wlan
Connect
IP Acquire
Full DHCP
process
IP Acquire
IP Acquire
Opportunistic
renew process
Full renew
process
DHCPv4 client
74
SWRU455A – February 2017 – Revised March 2017
Copyright © 2017, Texas Instruments Incorporated
Network Addresses
Status =
sl_NetCfgSet(SL_NETCFG_IPV4_STA_ADDR_MODE,SL_NETCFG_ADDR_FAST_RENEW_MODE_NO_WAIT_ACK,0,0);
if
( Status )
{
// error
}
•
Full DHCP Process
– The entire DHCP sequence is processed with every connection to the network.
Example:
_i16 Status;
Status = sl_NetCfgSet(SL_NETCFG_IPV4_STA_ADDR_MODE, SL_NETCFG_ADDR_DISABLE_FAST_RENEW,0,0);
if
( Status )
{
// error
}
shows the differences between the modes.
Figure 5-1. DHCPv4 IP Acquisition Modes
5.4.2 Address Release
By default the SimpleLink device does not release the DHCP address when Wi-Fi disconnect is
requested. However, in some use cases the release is required, even if the lease time is short due to
limited address range at the DHCP server. The SimpleLink device enables a special mode that releases
the IP address on requested WiFi disconnect commands from the host application. This mode is not
enabled by default.